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Photos: Courtesy of Marga Ree - www.rxroots.com
From: Marga Ree
Sent: Saturday, November 19, 2005 2:42 PM
Subject: [roots] Internal bleaching
This 40 year old woman wanted to have done something on the yellow
discoloration of 2.1. She recalled sustaining a trauma when she was 20 years of age,
after which the tooth turned yellow. No other signs or symptoms. Looking at the rad,
you can see a partial calcification in the coronal part of the canal.
At midroot level, a canal is clearly visible, although of an irregular shape.
After some troughing I found the original canal, which was very narrow to begin with,
but which became very wide at midroot level. There was profound bleeding upon entering
this part . It felt like a resorption defect. Apical foramen gauged with LS # 70, and a
dressing of Ca(OH)2.
Sec. session: application of an apical plug of MTA, and in the third session I finished
the RCT , and placed sodium perborate which I changed 3 times with time intervals of
2 weeks. Before I make the build-up of composite, I soak the access opening in 10%
sodium ascorbate for a couple of minutes, this acts as a kind of a scavenger,
to eliminate any residual oxygen, which can affect polymerization of resins.
Here is an old case, which I treated approx 5 years ago. I usually place a
barrier of RMGIC of 2 mm on top of the filling material (see yellow arrows),
and apply this with a needle tube. This means that the filling material should
be about 4 mm below the CEJ, so after the barrier of 2 mm is placed, there is
still 2 mm below the CEJ for the sodium perborate to be effective. I change
the sodium perborate every 2 weeks, if necessary. After having obtained a satisfactory
result, I remove the remnants of peroxide with the application of sodium ascorbate
for a couple of minutes, see below mentioned abstract. Then the usual acid etching,
priming and bonding for a composite build-up.
Below is a summary of Ben Schein on sodium ascorbate.
Sodium Ascorbate is a non-acidic form of Vitamin C, a major antioxidant as well
as one of the most important Vitamins required by the Human body on a regular
and ongoing basis may assist in the treatment of colds and flu by reducing the
severity and duration of symptoms . Sodium Ascorbate is a buffered form of Vitamin
C that consists of 90% Ascorbic Acid bound to 10% Sodium. It is sold in Nutrition
Holistic Vitamin Stores in liquid form. "Nutrition freaks" use on
a regular and ongoing basis because they think it assists in the treatment of
colds and flu by reducing the severity and duration of symptoms - Marga
1: J Dent Res. 2002 Jul;81(7):477-81.
Reversal of compromised bonding in bleached enamel.
Lai SC, Tay FR, Cheung GS, Mak YF, Carvalho RM, Wei SH, Toledano M, Osorio R, Pashley DH.
Oxygen inhibits polymerization of resin-based materials. We
hypothesized that compromised bonding to bleached enamel can be reversed with
sodium ascorbate, an anti-oxidant. Sandblasted human enamel specimens were treated
with distilled water (control) and 10% carbamide peroxide gel with or without
further treatment with 10% sodium ascorbate. They were bonded with Single Bond
(3M-ESPE) or Prime&Bond NT (Dentsply DeTrey) and restored with a composite.
Specimens were prepared for microtensile bond testing and transmission electron
microscopy after immersion in ammoniacal silver nitrate for nanoleakage evaluation.
Bond strengths of both adhesives were reduced after bleaching but were reversed
following sodium ascorbate treatment (P < 0.001). Resin-enamel interfaces
in bleached enamel exhibited more extensive nanoleakage in the form of isolated
silver grains and bubble-like silver deposits. Reduction of resin-enamel bond
strength in bleached etched enamel is likely to be caused by a delayed release
of oxygen that affects the polymerization of resin components.
1: Oper Dent. 2003 Nov-Dec;28(6):825-9.
Reversal of dentin bonding to bleached teeth.
Kaya AD, Turkun M.
Many studies have shown a considerable reduction in enamel
bond strength of resin composite restorations when the bonding procedure is
carried out immediately after bleaching. These studies claim that a certain
waiting period is needed prior to restoration to reach the original bond strength
values prior to bleaching. This study determined the effect of anti-oxidant applications
on the bond strength values of resin composites to bleached dentin. Ninety human
teeth extracted for orthodontic purposes were used in this study. The labial
surface of each tooth was ground and flattened until dentin appeared. The polished
surfaces were subjected to nine different treatments:
1) bleaching with gel (35% Rembrandt Virtuoso)
2) bleaching with gel + 10% sodium ascorbate (SA);
3) bleaching with gel + 10% butylhydroxyanisole (BHA);
4) bleaching with sol (35% hydrogen peroxide);
5) bleaching with sol + 10% sodium ascorbate;
6) bleaching with sol + 10% BHA;
7) bleaching with gel + immersed in artificial saliva for seven days;
8) bleaching with sol + immersed in artificial saliva for seven days;
9) no treatment.
After bonding application, The resin composite in standard dimensions was applied
to all specimens. The teeth were stored in distilled water at 37 degrees C for
24 hours and a universal testing machine determined their resistance to shear
bond strength. The data was evaluated using ANOVA and Duncan tests. Bond strength
in the bleached dentin group significantly decreased compared to the control
group. On the other hand, the antioxidant treatment had a reversal effect on
the bond strength to dentin. After the bleaching treatment, the 10% sodium ascorbate
application was effective in reversing bond strength. In the samples where antioxidant
was applied after the bleaching process, bonding strength in dentin tissue was
at the same level as those teeth kept in artificial saliva for seven days.
J Oral Rehabil. 2004 Dec;31(12):1184-91.
Effect of 10% sodium ascorbate on the shear bond strength
of composite resin to bleached bovine enamel.
Turkun M, Kaya AD.
Department of Restorative Dentistry and Endodontics, School of Dentistry,
Ege University, Izmir, Turkey.
summary The purpose of this study was to comparatively investigate
the effect of antioxidant treatment and delayed bonding after bleaching with
three different concentrations of carbamide peroxide (CP) on the shear bond
strength of composite resin to enamel. One hundred flat buccal enamel surfaces
obtained from bovine incisors were divided into three bleaching groups of 10,
16 and 22% CP (n = 30) and a control group. Each bleaching group was then divided
into three subgroups (n = 10). Group 1 consisted of specimens bonded immediately
after bleaching. Group 2 specimens were treated with antioxidant agent, 10%
sodium ascorbate, while Group 3 specimens were immersed in artificial saliva
for 1 week after bleaching. Specimens in the control group were not bleached.
After the specimens were bonded with Clearfil SE Bond and Clearfil AP-X, they
were thermocycled and tested in shear until failure. Fracture analysis of the
bonded enamel surface was performed using scanning electron microscope. The
shear bond strength data was subjected to one-way analysis of variance followed
by Duncan's multiple range test at a significance level of P < 0.05. Shear
bond strength of composite resin to enamel that was bonded immediately after
bleaching with 10, 16 and 22% CP was significantly lower than that of unbleached
enamel (P < 0.05). For all three bleaching groups, when the antioxidant-treated
and delayed bonding (1 week) subgroups were compared with the control group,
no statistically significant differences in shear bond strength were noted (P
Marga, I thought the whole point of
the barrier was to block from the Sodium Perborate to get to the CEJ and cause
external resorption. Why do you place a barrier at all, if you let the Perborate
into the CEJ (which may be incomplete) ? - Thomas
Thomas, To my knowledge, there never has been reported an external
root resorption following bleaching with the use of sodium perborate. Secondly,
in order to get an esthetic result, you should remove any filling material approx
2 mm below the CEJ, due to the direction of the dentinal tubules.
My rationale for placing a barrier is that I want to prevent
leakage along the root canal filling, and I usually perform bleaching in the
same session as the obturation. But this applies to the use of gp and sealer.
You should protect the root filling, because it has not completely set at the
time of obturation. I use Resilon nowadays, so maybe it is not necessary at
all to use a barrier. I don't know, but I guess it doesn't do any harm either.
1: J Endod. 1991 Aug;17(8):365-8.
Intracoronal isolating barriers: effect of location on root leakage and
effectiveness of bleaching agents
Costas FL, Wong M. United States Army Dental Activities, Ft. Gordon, SC.
The purpose of this study was to evaluate the ability of several
intracoronal isolating barrier materials to prevent leakage of a bleaching agent
into the roots of teeth and to determine whether placement of the barrier material
at the cementoenamel junction or below the cementoenamel junction has an effect
on the bleaching results of the crowns. Fifty teeth were stained in vitro, and
gutta-percha fillings were placed in the root canals. The experimental isolating
barriers were placed at the cementoenamel junction or 2 mm below the cementoenamel
junction. A walking bleach of Superoxol and sodium perborate was placed in the
pulp chamber for three treatments. The roots of the teeth were evaluated for
the presence of root decoloration, and the crowns of the teeth were evaluated
for bleaching effect. Findings from this study showed a significant difference
between gutta-percha alone and gutta-percha with barrier in preventing root
decoloration (p less than 0.05). No significant differences were found between
the other experimental groups in preventing root decoloration. Placement of
an intracoronal isolating barrier material 2 mm below the cementoenamel junction
resulted in a more acceptable esthetic bleaching result of the crowns than did
placement of barrier material at the cementoenamel junction.
For what it is worth Thomas, I have always
done it the way marga presented, although I was never aware of a resorption
issue. I did it to protect the fill and to allow for a deeper bleaching to present
excess discoloration at the cej. - gary
Prof. Rotstein, who was my specialisation
director gave us a paper explaining the barrier shouldn't be flat, because the
CEJ is higher on the M&D aspects of the roots and the barrier should follow
The whole point is to prevent O2 reaching
the CEJ and causing resorption. No resorption was reported with Sodium Perborate,
but many attributed it to this barrier on the CEJ. I am not sure there can be
a problem with Sodium Perborate entering the root filling after it's set (but
who knows). Estheticly, for sure it's better to place the Perborate bellow CEJ.
- Go figure, Thomas
From: Marga Ree
Sent: Friday, February 03, 2006 6:51 PM
Subject: [roots] Internal bleaching with sodium perborate
I have posted this case earlier, but I wanted to show an example of internal bleaching
with the use of sodium perborate, I would not recommend to use hydrogen peroxide in
high a concentration, see also my response to Jeremy's post on internal bleaching - Marga
beautiful case and results Marga - Rob
I've done this very succesfully for years
Rubber dam is mandatory as well as protective eyewear for everyone in the room
I make a mix with Amosan powder and Hydrogen peroxide solution
The best sources of the H2O2 solutions are hairdressers who usually take deliveries of
30, 60 or 90 vols solutions
The strongest you can get is 100 vols (about 33% solution ) but it is very caustic -
get your pharmacist to mix it fresh Keep it in a dark brown bottle in the dark, date it
and get fresh mix after 6 weeks
The peroxide will turn the fat/oils in you skins to soap instantly so wear surgical gloves
Failure of treatment can usually be traced to failure to follow all of the above Re storage
/ disposal / fresh solution
I use a cotton pellet then ZnPo4 for sealing the cavity
Make sure you only go about 2 to 3mm subgingival in your canal preparation.
Have the patient ring you if they experience pain
Usually happens because you went deeper than 2 to 3 mm
I've had really dark teeth go whiter than the contralateral tooth within 24 hours
Hope this helps
My father gave me the recipe he did endo for 56 referring dentists - Jeremy Rourke
Jeremy, I respectfully disagree with you recommendation to use hydogen peroxide for
internal bleaching procedure, as this agent can have some serious side effects. A safer
choice is the use of sodium perborate. A very good review article on this topic has been
published in the IEJ of May 2003, I have listed their conclusion below here - Marga
Review of the current status of tooth whitening with the walking bleach technique
T. Attin, F. Paque¤ , F. Ajam & A . M. Lennon
Discoloured root-filled teeth can be successfully treated using the walking bleach technique.
Bleaching is performed by temporarily placing a mixture of sodiumperborate-( tetrahydrate)
and water into the pulp chamber. This mixture releases H2O2 which is able to react with the
staining substances. In the case of severe and refractory discolouration, 3% H2O2
could be used instead of water. It is not advisable to use the thermocatalytic methodwith
heatingof a 30%H2O2 solution, as this procedure increases the risko f external cervical
resorption. For the same reason, 30% H2O2 should also not be used for the walking bleach
technique. In order to prevent seepage of H2O2 through dentine, it is necessary to place a
dense root filling and an additional cervical seal prior to starting the walking bleach procedure.
For long-term success, it seems to be important to restore the access cavity with an adhesive
filling, which prevents leakage of bacteria and stains.
Marga....you were close on your citation...but see the one I did...Madison and Walton did the
study in Dogs...and I'm sure this review article referenced that. I thought you should know
so you get the source. - Joey D
Jeremy, The only problem with using this technique is that it's associated with increased
Walton did a study in Dogs that is considered a classic...while the abstract is not quite perfect...
they found increased resorption with heat OR superoxide/33% H2O2
J Endod. 1990 Dec;16(12):570-4. Related Articles, Links
Cervical root resorption following bleaching of endodontically treated teeth.
Madison S, Walton R.
University of North Carolina School of Dentistry, Chapel Hill.
One year following root canal treatment and internal etching and bleaching
of anterior teeth in dogs, the animals were sacrificed and the teeth
prepared for stereomicroscopic or light microscopic examination. Evidence of
cervical root resorption and ankylosis was noted on several teeth. The
bleaching factors associated with the teeth exhibiting resorption were heat
with 30% hydrogen peroxide. Resorption was not related to walking bleach or
to internal etching alone. - Joey D